R. La Starza et al., Characterization of 12p molecular events outside ETV6 in complex karyotypes of acute myeloid malignancies, BR J HAEM, 107(2), 1999, pp. 340-346
Acute myeloid disorders with rearrangements of 12p outside the ETV6 gene we
re characterized by fluorescence in situ hybridization (FISH) with a panel
of DNA probes. Seven patients with de novo acute myeloid leukaemia (AML), o
ne with secondary acute myeloid leukaemia (sAML), and one in the blast phas
e of chronic myeloid leukaemia (CML-BP) were enrolled in the study. All AML
cases showed multiple karyotypic changes. Chromosome 5 and/or 7 deletions
were the most frequent accompanying changes. FISH revealed amplification, c
ryptic translocation, and fragmentation of chromosome 12, not discernible a
t karyotypic level. Different karyotypic rearrangements of 12p showed a com
mon molecular event. Among the seven cases in which breakpoints could be de
termined, six were telomeric and one centromeric to ETV6. In three AML case
s a new recurrent breakpoint in the telomeric region was identified distall
y to locus D12S158 and to pac 922B22 which is the most telomeric probe avai
lable for 12p. Accompanying cryptic deletions were also detected in five pa
tients and the commonly deleted region, of around 700 kb, included the ETV6
gene and the D12S391 locus.